function avg=myMean(pliXT)
nTrials=size(pliXT,1)
nch=size(pliXT,2)
for i=1:nTrials
    x=squeeze(pliXT(i,:,:));
    indx=logical(tril(ones(nch,nch),-1))
    avg(i)=sum(x(indx))/((nch*(nch-1))/2); 
    
end
